Depression remains largely under-diagnosed in the male population. While men are diagnosed at lower rates than women, men commit suicide at rates that are 4 to 18 times higher than women, depending on the age group.

LAFAYETTE, Calif. — High school sophomore Kelly Morimoto says when her friend first came to her to talk about his depression she was “shocked.” No one, after all, had ever spoken to her about how to respond in these kinds of situations...